This invention relates to shuttle cleaning of heat exchanger tubes and is an improvement over the concepts disclosed in the above-identified patents.
It is known from U.S. Pat. Nos. 3,319,710 and 4,124,065 to connect individual elongated cleaning element capturing cages or baskets to both ends of longitudinally extending tubes disposed in a heat exchanger housing. The tube ends are held in position at both ends by transverse tube sheets. The baskets are adapted to contain shuttlable cleaning elements, such as brushes. Fluid flowing in one direction through the tubes keeps the cleaning elements captured within their respective basket chambers, while the fluid discharges outwardly through slot-like openings in the basket walls. Upon reversal of fluid flow, the cleaning elements are forced out of their baskets and through the tubes to the baskets at the opposite tube ends to thereby perform a tube cleaning action.
In the known prior devices, the cleaning element capturing cages have been mounted for communication with the tubes by securing them into the same openings in the tube sheets that the tube ends are secured into. They have been press fit either into the tube ends themselves, or directly into the tube sheet openings. See the above-identified patents.
While the press-fitting of the cages into the tube sheets provides for a good connection therebetween, this method of assembly poses certain problems. Hundreds, if not thousands, of cages may need to be utilized in any given heat exchanger installation. To press-fit each and every cage into the tube sheets is a time consuming laborious task. Furthermore, if one or more cages needs to be removed for servicing, replacement or for gaining access to the tube interiors, disconnection of the cage or cages is also difficult.
It is a task of the present invention to provide an improved mounting for heat exchanger tube cleaner capturing cages which substantially solves the aforementioned problems and permits quick and easy mounting or release of the cages from their support.
In accordance with various aspects of the invention, the inner ends of the cleaning element capturing cages are provided with enlarged collars having generally semi-circular flanges providing inclined undercut seats. The heat exchanger tube ends extend fully through the openings in the tube sheets and are provided with annular flared lips extending outwardly from the outer tube sheet faces. The cages are mounted directly to the tubes by bringing the collar seats down into hanging engagement with the tube lips.